Caesar cipherCaesar cipher, is one of the simplest and most widely known encryption techniques.
The transformation can be represented by aligning two alphabets,
the cipher alphabet is the plain alphabet rotated left or right by some number of positions.
When encrypting, a person looks up each letter of the message in the 'plain'
line and writes down the corresponding letter in the 'cipher' line. Deciphering is done in reverse.
The encryption can also be represented using modular arithmetic
by first transforming the letters into numbers, according to the scheme, A = 0, B = 1,..., Z = 25.
Encryption of a letter x by a shift n can be described mathematically as
Plaintext: binman

cipher variations:

cjonbo

dkpocp

elqpdq

fmrqer

gnsrfs

hotsgt

iputhu

jqvuiv

krwvjw

lsxwkx

mtyxly

nuzymz

ovazna

pwbaob

qxcbpc

rydcqd

szedre

tafesf

ubgftg

vchguh

wdihvi

xejiwj

yfkjxk

zglkyl

ahmlzm

Decryption is performed similarly,
(There are different definitions for the modulo operation.
In the above, the result is in the range 0...25. I.e., if x+n or x-n are not in the range 0...25,
we have to subtract or add 26.)
Read more ...Atbash CipherAtbash is an ancient encryption system created in the Middle East.
It was originally used in the Hebrew language.
The Atbash cipher is a simple substitution cipher that relies on
transposing all the letters in the alphabet such that the resulting alphabet is backwards.
The first letter is replaced with the last letter, the second with the second-last, and so on.
An example plaintext to ciphertext using Atbash:

Baconian CipherTo encode a message, each letter of the plaintext is replaced by a group of five of the letters 'A' or 'B'.
This replacement is done according to the alphabet of the Baconian cipher, shown below.

Affine CipherIn the affine cipher the letters of an alphabet of size m are first mapped to the integers
in the range 0..m - 1. It then uses modular arithmetic to transform the integer that each plaintext
letter corresponds to into another integer that correspond to a ciphertext letter.
The encryption function for a single letter is
where modulus m is the size of the alphabet and a and b are the key of the cipher.
The value a must be chosen such that a and m are coprime.Considering the specific case of encrypting messages in English (i.e. m = 26),
there are a total of 286 non-trivial affine ciphers, not counting the 26 trivial Caesar ciphers.
This number comes from the fact there are 12 numbers that are coprime with 26 that are less than 26
(these are the possible values of a). Each value of a can have 26 different addition shifts (the b value)
; therefore, there are 12*26 or 312 possible keys.Plaintext: binman

cipher variations:

cjonbo

ezolbo

gpojbo

ifohbo

kvofbo

mlodbo

qrozbo

shoxbo

uxovbo

wnotbo

ydorbo

atopbo

dkpocp

fapmcp

hqpkcp

jgpicp

lwpgcp

nmpecp

rspacp

tipycp

vypwcp

xopucp

zepscp

bupqcp

elqpdq

gbqndq

irqldq

khqjdq

mxqhdq

onqfdq

stqbdq

ujqzdq

wzqxdq

ypqvdq

afqtdq

cvqrdq

fmrqer

hcroer

jsrmer

lirker

nyrier

porger

turcer

vkraer

xaryer

zqrwer

bgruer

dwrser

gnsrfs

idspfs

ktsnfs

mjslfs

ozsjfs

qpshfs

uvsdfs

wlsbfs

ybszfs

arsxfs

chsvfs

exstfs

hotsgt

jetqgt

lutogt

nktmgt

patkgt

rqtigt

vwtegt

xmtcgt

zctagt

bstygt

ditwgt

fytugt

iputhu

kfurhu

mvuphu

olunhu

qbulhu

srujhu

wxufhu

ynudhu

adubhu

ctuzhu

ejuxhu

gzuvhu

jqvuiv

lgvsiv

nwvqiv

pmvoiv

rcvmiv

tsvkiv

xyvgiv

zoveiv

bevciv

duvaiv

fkvyiv

havwiv

krwvjw

mhwtjw

oxwrjw

qnwpjw

sdwnjw

utwljw

yzwhjw

apwfjw

cfwdjw

evwbjw

glwzjw

ibwxjw

lsxwkx

nixukx

pyxskx

roxqkx

texokx

vuxmkx

zaxikx

bqxgkx

dgxekx

fwxckx

hmxakx

jcxykx

mtyxly

ojyvly

qzytly

spyrly

ufyply

wvynly

abyjly

cryhly

ehyfly

gxydly

inybly

kdyzly

nuzymz

pkzwmz

razumz

tqzsmz

vgzqmz

xwzomz

bczkmz

dszimz

fizgmz

hyzemz

jozcmz

lezamz

ovazna

qlaxna

sbavna

uratna

wharna

yxapna

cdalna

etajna

gjahna

izafna

kpadna

mfabna

pwbaob

rmbyob

tcbwob

vsbuob

xibsob

zybqob

debmob

fubkob

hkbiob

jabgob

lqbeob

ngbcob

qxcbpc

snczpc

udcxpc

wtcvpc

yjctpc

azcrpc

efcnpc

gvclpc

ilcjpc

kbchpc

mrcfpc

ohcdpc

rydcqd

todaqd

vedyqd

xudwqd

zkduqd

badsqd

fgdoqd

hwdmqd

jmdkqd

lcdiqd

nsdgqd

pideqd

szedre

upebre

wfezre

yvexre

alevre

cbetre

ghepre

ixenre

knelre

mdejre

otehre

qjefre

tafesf

vqfcsf

xgfasf

zwfysf

bmfwsf

dcfusf

hifqsf

jyfosf

lofmsf

nefksf

pufisf

rkfgsf

ubgftg

wrgdtg

yhgbtg

axgztg

cngxtg

edgvtg

ijgrtg

kzgptg

mpgntg

ofgltg

qvgjtg

slghtg

vchguh

xsheuh

zihcuh

byhauh

dohyuh

fehwuh

jkhsuh

lahquh

nqhouh

pghmuh

rwhkuh

tmhiuh

wdihvi

ytifvi

ajidvi

czibvi

epizvi

gfixvi

klitvi

mbirvi

oripvi

qhinvi

sxilvi

unijvi

xejiwj

zujgwj

bkjewj

dajcwj

fqjawj

hgjywj

lmjuwj

ncjswj

psjqwj

rijowj

tyjmwj

vojkwj

yfkjxk

avkhxk

clkfxk

ebkdxk

grkbxk

ihkzxk

mnkvxk

odktxk

qtkrxk

sjkpxk

uzknxk

wpklxk

zglkyl

bwliyl

dmlgyl

fcleyl

hslcyl

jilayl

nolwyl

peluyl

rulsyl

tklqyl

valoyl

xqlmyl

ahmlzm

cxmjzm

enmhzm

gdmfzm

itmdzm

kjmbzm

opmxzm

qfmvzm

svmtzm

ulmrzm

wbmpzm

yrmnzm

binman

dynkan

fonian

hengan

junean

lkncan

pqnyan

rgnwan

twnuan

vmnsan

xcnqan

zsnoan

The decryption function iswhere a - 1 is the modular multiplicative inverse of a modulo m. I.e., it satisfies the equationThe multiplicative inverse of a only exists if a and m are coprime.
Hence without the restriction on a decryption might not be possible.
It can be shown as follows that decryption function is the inverse of the encryption function,Read more ...

ROT13 CipherApplying ROT13 to a piece of text merely requires examining its alphabetic
characters and replacing each one by the letter 13 places further along in the alphabet,
wrapping back to the beginning if necessary. A becomes N, B becomes O, and so on up to M,
which becomes Z, then the sequence continues at the beginning of the alphabet: N becomes A,
O becomes B, and so on to Z, which becomes M. Only those letters which occur in the English
alphabet are affected; numbers, symbols, whitespace, and all other characters are left unchanged.
Because there are 26 letters in the English alphabet and 26 = 2 * 13, the ROT13 function is its own inverse:

Polybius SquareA Polybius Square is a table that allows someone to translate letters into numbers.
To give a small level of encryption, this table can be randomized and shared with the recipient.
In order to fit the 26 letters of the alphabet into the 25 spots created by the table, the letters
i and j are usually combined.

1

2

3

4

5

1

A

B

C

D

E

2

F

G

H

I/J

K

3

L

M

N

O

P

4

Q

R

S

T

U

5

V

W

X

Y

Z

Basic Form:

Plain:

binman

Cipher:

214233231133

Extended Methods:Method #1

Plaintext: binman

method variations:

gosrfs

mtxwlx

rycbqc

wdhgvh

Method #2Bifid cipherThe message is converted to its coordinates in the usual manner, but they are written vertically beneath:

b i n m a n
2 4 3 2 1 3
1 2 3 3 1 3

They are then read out in rows:
243213123313Then divided up into pairs again, and the pairs turned back into letters using the square:

Permutation CipherIn classical cryptography, a permutation cipher is a transposition cipher in which the key is a permutation.
To apply a cipher, a random permutation of size E is generated (the larger the value of E the more secure the cipher).
The plaintext is then broken into segments of size E and the letters within that segment are permuted according to
this key.
In theory, any transposition cipher can be viewed as a permutation cipher where E is equal to the
length of the plaintext; this is too cumbersome a generalisation to use in actual practice, however.
The idea behind a permutation cipher is to keep the plaintext characters unchanged,
butalter their positions by rearrangement using a permutation
This cipher is defined as:Let m be a positive integer, and K consist of all permutations of {1,...,m}For a key (permutation) , define:
The encryption function The decryption function A small example, assuming m = 6, and the key is the permutation
:The first row is the value of i,
and the second row is the corresponding value of (i)The inverse permutation, is constructed by interchanging the two rows,
andrearranging the columns so that the first row is in increasing order, Therefore, is:
Total variation formula: e = 2,718281828 , n - plaintext length